How to delete empty subfolders with PowerShell?

I have a share that is a "junk drawer" for end-users. They are able to create folders and subfolders as they see fit. I need to implement a script to delete files created more than 31 days old.

I have that started with Powershell. I need to follow up the file deletion script by deleting subfolders that are now empty. Because of the nesting of subfolders, I need to avoid deleting a subfolder that is empty of files, but has a subfolder below it that contains a file.

For example:

• FILE3a is 10 days old. FILE3 is 45 days old.
• I want to clean up the structure removing files older than 30 days, and delete empty subfolders.

C:\Junk\subfolder1a\subfolder2a\FILE3a

C:\Junk\subfolder1a\subfolder2a\subfolder3a

C:\Junk\subfolder1a\subfolder2B\FILE3b

Desired result:

• Delete: FILE3b, subfolder2B & subfolder3a.
• Leave: subfolder1a, subfolder2a, and FILE3a.

I can recursively clean up the files. How do I clean up the subfolders without deleting subfolder1a? (The "Junk" folder will always remain.)

I would do this in two passes - deleting the old files first and then the empty dirs:

Get-ChildItem -recurse | Where {!$_.PSIsContainer -and `
$_.LastWriteTime -lt (get-date).AddDays(-31)} | Remove-Item -whatif

Get-ChildItem -recurse | Where {$_.PSIsContainer -and `
@(Get-ChildItem -Lit $_.Fullname -r | Where {!$_.PSIsContainer}).Length -eq 0} |
Remove-Item -recurse -whatif

This type of operation demos the power of nested pipelines in PowerShell which the second set of commands demonstrates. It uses a nested pipeline to recursively determine if any directory has zero files under it.